EA039804B1 - Heat exchanger closure assemblies and methods of using and installing the same - Google Patents

Abstract

Provided is a heat exchanger assembly including an elongated tubular heat exchanger enclosure defining an interior chamber. A tube sheet is positioned within the interior chamber of the heat exchanger enclosure separating the interior chamber into a shell side and a channel side. The interior portion is configured to removably receive a tube bundle positioned within the shell side of the interior chamber. An annular sleeve member is positioned within the channel side of the interior chamber of the heat exchanger enclosure. An annular elastic torsion member is positioned within the channel side of the interior chamber of the heat exchanger such that the sleeve member is positioned between the tube sheet and the elastic torsion member. The elastic torsion member has an inner circumference deflectable relative to its outer circumference for torsioning the elastic torsion member.

Description

Cross-reference to related application

This application claims priority to U.S. Patent Application No. 62/645,662, filed March 2018, which is hereby incorporated by reference in its entirety.

The technical field to which the invention belongs

The proposed embodiments relate to heat exchanger closures and methods of their use and installation, more specifically to closure systems and methods for sealing high-pressure shell-and-tube type heat exchangers having removable tube bundles, and more specifically to heat exchanger closures configured to withstand varying thermal loads having a stopper assembly, which is attached to the heat exchanger channel by means of a shut-off assembly.

State of the art

Shell and tube heat exchangers form the bulk of non-fired heat transfer equipment in chemical plants, refineries, thermal power plants and similar facilities. Among the most popular heat exchangers of the main types of shell-and-tube heat exchangers currently in use are those having removable tube bundles, such as U-tubes with a floating head, or having fixed bundles with fixed tube sheets. In practice, it is usually desirable to have a removable tube bundle so that the heat exchanger can be taken out of service periodically, the tube bundle removed for cleaning and visual inspection, and then reassembled. It may also be desirable to hydrostatically or pneumatically test the shell side of tube bundle heat exchangers in such a way that visual inspection or inspection of tube connections and tubesheet gaskets is possible and leaks can be easily located and repaired. To remove the bundle, a closure should be provided that can be opened quickly and reliably after a long period of operation under varying thermal and pressure loads. The problems associated with disassembly, extraction, hydrostatic and pneumatic testing and reassembly are especially acute when the tube heat exchanger is relatively large (over 9144 cm (36 in) in diameter) and is designed for high pressure operations in excess of 689475 MPa (1000 lb -force per square inch) as the weight of the required internal components becomes large. A particular type of closure that has been developed for this purpose is a threaded plug, also known as a turbine ring lock type closure, which uses a plurality of interlocking threads to secure the lock ring cap assembly in place. The main advantage of this type of system is that it eliminates the large duct cover flange and bolting of other high pressure heat exchanger designs. There are two general classifications of screw plug type heat exchangers described in the prior art. In applications where pressures exceed 689,475 MPa (1,000 psi) on both sides of the tubesheet, so that the tubesheet itself is subjected to only less pressure drop, a fully removable style A closure can be provided, whereby the bundle can be removed without removing the housing cover. If the pressure difference is too high, it is more convenient to remove the casing cap to gain access to the bundle, in which case a style B closure could be used.

Moreover, the closures used in this type of heat exchanger must be rigid enough to withstand internal pressure without significant movement of the closure relative to the channel, as this will lead to partial or complete separation of the threads used to secure the closure. However, the assembly must also be flexible enough to withstand the anticipated thermal stresses that occur during operation. Expected thermal loads are the temperature changes over time that may occur during initial start-up or subsequent repairs, or in the event of a process disruption or plant shutdown, any single event of which could result in differential thermal expansion of internal components relative to the duct. Thermal loads, if not properly handled in one or more embodiments, can in turn cause uneven plastic deformation of the internal components such that the load on the gaskets is no longer evenly distributed and eventually the assembly begins to leak. In particular, since the internal components of a heat exchanger are often subject to higher thermal expansion than the duct due to differing coefficients of thermal expansion or the fact that thinner components can heat up at a faster rate than thick duct materials, a rigid closure is undesirable if it is leads to plastic deformation of internal components, which leads to gasket unloading and leakage; and higher stress on the threaded portions of the closure and channel, which can lead to thread distortion. All the aforementioned circumstances and operating conditions have led to the adoption of many different technical solutions that have been only partially successful because they solved only some of the problems while introducing others, which is especially true for applications where temperature, pressure and dimensions typical on the high pressure side.

In all of these prior art solutions, the threaded closure ring and lid assembly (or closure plug) must be rotated several times, typically 20 or more, to fully engage the threads in the closure ring with the threads in the heat exchanger channel. Special attention must be paid to this as the locking ring assembly must be accurately centered and supported while being outside of the channel when rotated into position. In particular, since the weight of the cork cannot be allowed to rest on the threads, the accuracy of handling such a heavy piece of equipment (as much as 9,450 kg (21,000 lb)) requires a specialized jig supplied with the heat exchanger. Various designs of clamping devices have been developed. In some cases, a cantilever counterweight system is used to balance the weight of the locking ring. In other cases, the jig is attached directly to the channel.

However, the special clamping device has no other function and therefore can be used infrequently, so that the team working on the heat exchanger has no experience in this context, and in their actions is completely guided by the instructions provided by the manufacturer. In the worst case, there is a risk of injury to production personnel working on the heat exchanger if the heavy assembly is not properly secured in the jig. There is always a risk that the cork may get stuck or the threads may be damaged during insertion or removal. This is true in particular when the closure plug is first inserted into the heat exchanger channel. During shutdowns or repairs, time is critical, so any unplanned downtime associated with a stuck cap can result in a significant financial loss for a chemical or refinery.

The difficulty of manipulating the locking ring means that it is undesirable to insert and remove the locking ring more than once during a maintenance event. If repairs are to be made on pipes or other pressure components, a hydrostatic or pneumatic annulus test should be performed without the cap in place to make a visual inspection to ensure there are no leaks. Previous designs have included the use of a temporary inner flange to stress the gasket during pressure testing of the annular space of the heat exchanger. Later designs, such as that shown in US Pat. No. 4,750,554, provide a mechanism for applying the load from the inner flange in parallel with the load from the inner row of bolts. For these later designs, the inner row of bolts found in the outer locking ring is used to stress the tubesheet gasket only in the event of a leak. The internal components required to achieve this function can be quite complex, and although the design has been properly optimized, the number of parts and complexity increase the risk of improper assembly and increased manufacturing costs. Since the inner flange is in contact with the process fluid, the bolts may become corroded or coated with coke and will need to be cut or drilled out. Moreover, differential thermal expansion of internal components can cause damage or deformation of the inner flange assembly, making it difficult to remove and reuse the assembly.

Therefore, prior art solutions do not solve the problem of handling the closure during insertion and removal, as well as providing pressure testing while maintaining a simpler design for internal components.

Although the heat exchanger screw cap may meet the design code for pressurized parts, within the design boundary of pressurized equipment, there are other components that will affect the cost of ensuring the reliability and service life of this type of equipment. There is a need for a device that is rigid enough to limit movement under pressure load while avoiding damage to internal components under anticipated thermal loading conditions and providing fail-safe protection to pressurized structure (threads), etc. under extreme thermal stress.

Therefore, there is an unmet need in the prior art for heat exchanger closures that are configured to withstand varying thermal loads and that include a locking ring and cap that can be more easily installed and removed as required without the use of specialized handling equipment.

The essence of the invention

The purpose and advantages of the illustrated embodiments described below will be set forth in the following description and become clear from it. Additional advantages of the illustrated embodiments will be realized and achieved by means of devices, systems and methods, information about which is specifically emphasized in the written description and claims, and

- 2 039804 also follow from the attached drawings.

In order to achieve these and other advantages, and in accordance with the purpose of the illustrated embodiments in one aspect, closure systems and methods are described for shell-and-tube type heat exchangers in which the closures of the heat exchangers are configured to withstand varying thermal loads and which include a locking ring attached to the channel. heat exchanger using a plurality of interlocking hubs or threads.

As noted earlier, the following are of particular concern to end users of shell-and-tube heat exchangers:

leakage through the gaskets, leading to the release of process fluids, such as hydrogen and/or hydrocarbons, into the environment;

technological leaks between the fluid environments of the annular space and the in-line space;

longer than expected maintenance times due to cap jamming during insertion and removal; and the complexity of the large number of internal components and specialized equipment required to support the closure during insertion or removal.

In accordance with certain embodiments illustrated herein, methods and systems now disclosed for opening, closing, and sealing a high pressure heat exchanger involve the use of a lid assembly and a locking ring (e.g., a closure plug) whereby the closure plug is inserted into the heat exchanger passage in a single linear movement. and preferably rotated by less than one single turn (eg less than 360° turn) to the locked position. The load-bearing surfaces (eg hubs) are preferably not in contact until a final twist is applied effectively sealing the closure plug into the high pressure heat exchanger. The high pressure heat exchanger channel is preferably machined to form a first set of hubs and the locking ring is machined to form a second complementary set of hubs such that when the cork is rotated, the first set of hubs disengageably engages with the second set of hubs. In certain embodiments, a guide may be attached to one or more hub sets on the closure ring and/or channel to provide a raised section along one side that (i) prevents over-rotation, (ii) provides a bearing surface for insertion of the closure ring assembly, and (iii) prevent damage to load-bearing surfaces.

In certain exemplary embodiments, the lock ring is machined to some prescribed number (eg, 8) of lock ring hub sets and the heat exchanger channel is machined to some appropriate number of channel hub sets. Those skilled in the art will readily appreciate that within the scope of the inventive aspects of the present invention, the number of respective hub sets may be varied. In certain exemplary embodiments, the hub profile is some form of thrust thread.

It should be understood that certain advantages of the illustrated embodiments include a closure assembly that can be mounted with a single linear movement and without the need for a specialized jig or tool. Once the stopper assembly is in position, where it is fully supported on the heat exchanger channel, it is closed by a single partial turn (eg turning the stopper by 22.5°). The risk of the sealing plug sticking in relation to the heat exchanger channel is eliminated. In addition, handling of the stopper becomes safer, since rotation is not required until the stopper is fully supported against the heat exchanger. Easily accessible equipment such as cranes, bundle tractors and fork lift trucks can be used to move the closure to the desired location, thereby eliminating the cost associated with a specialized clamping fixture. Mounting is made safer because the locking ring assembly and plug do not have to be rotated at the same time, leaving them suspended and centered by counterweights or a cantilever, but instead preferentially slide along specially designed guides that also serve to provide support when turning. The guides are sized to ensure that the closure ring assembly of the closure will rest with its entire weight on the load-bearing surfaces of the hubs.

According to the illustrated embodiments, the insertion and removal of the closure assembly can be carried out faster than in the case of known threaded construction. Faster insertion and removal allows the use of simplified internal components, in particular by eliminating the need for an internal flange. In certain embodiments, only a partial turn is required to lock the cap assembly ring in place.

- 3 039804 (for example, a rotation of 22.5°) of the stopper assembly relative to the heat exchanger tube, as opposed to the typical 20 or more complete turns according to the known design. The result is flexibility in choosing the shape of the load-bearing surface of the closure, allowing it to be more optimal than the traditional inch trapezoid thread used in prior art.

With respect to known designs and methods, tightening a screw thread is comparable to driving a wedge into a gap until it quickly jams due to friction and slight plastic deformation. Thus, the thread must advance some linear distance during the turning process in order to achieve full engagement. Known designs typically use trapezoidal threads, typically in 25.4 mm (1 inch) pitch, so that one full turn can advance 25.4 mm (1 inch) into the canal. In contrast, hub designs according to certain illustrated embodiments of the present invention have, for example, interlocking or interlocking geometry with male and female threads that engage by co-rotation and that preferably utilize the shape of the hubs (e.g., thrust configuration). threads), which is stiffer and more suitable when the force on the hub is applied mainly in one direction. The hubs are provided with guides that are configured to ensure that the locking ring of the plug assembly is properly centered during insertion and does not over-rotate. The guides also function to protect the hubs during assembly of the cork closure with the heat exchanger tube.

Thus, a distinct advantage provided by the illustrated embodiments is the elimination of the need for specialized jigs required to support and center the closure ring as it rotates. In accordance with the illustrated embodiment of the present invention, the rotation of the stopper occurs once the closing ring of the stopper is fully inserted into the channel, so that the design of the closing ring significantly reduces the time spent opening and closing the heat exchanger for maintenance operations, eliminating the need for special equipment for loading and unloading operations and thus reduces the risk of improper installation resulting in leakage. By reducing opening and closing times, the internal flange used for pressure testing can also be eliminated, greatly reducing the number of components that must be inserted and/or removed to gain access to the tube bundle.

It should be noted that the illustrated embodiments of the present invention are directed to the creation of heat exchange structures that allow thermal expansion under changing thermal loads during operation through the use of an element subjected to elastic torsion. Considering the expected thermal expansion, by means of an element subjected to elastic torsion, sealing can be maintained over numerous operating cycles without adjusting the compression bolts on the closure. Expected thermal loads include heating and cooling of components due to startup, shutdown, fluctuations in fluid flow rates, and infrequent but predictable events such as a plant shutdown or sudden emergency shutdown. In the event of an extreme thermal load that causes thermal expansion of the internal components outside of the design range, it is critical to protect the closure hubs from damage, so the torsion element is designed to be configured to yield plastic deformation above a certain range of elastic deflection. . It will be understood that prior art designs and methods have required the use of specialized assembly procedures to maintain the sealing of the internal lining of the tubesheet, often entailing re-tightening the compression bolts during operation. Even with these procedures, plastic deformation of internal components due to differential thermal expansion may occur during operation. As noted above, the present invention circumvents this difficulty.

In accordance with certain illustrative embodiments of the present invention, sealing assemblies have been developed for sealing a high pressure shell and tube heat exchanger, which are shaped like a threaded plug and which maintain a seal against the heat exchanger tube sheet under pressure and varying thermal loads. The outer sealing of the closure assembly is preferably provided by a diaphragm and gasket assembly. The sealing of the diaphragm gasket is preferably maintained by the outer row of jack bolts, and the inner seal is preferably provided by a second gasket located at the tube sheet which is loaded by the inner row of jack bolts. In accordance with certain illustrated embodiments, the internal sealing load of the heat exchanger tube sheet is transmitted through the compression ring, the elastic torsion member, and the sleeve member. It should be understood that the element subjected to elastic torsion is supported in areas where it contacts the sleeve element and works on

- 4 039804 compression ring.

During the assembly procedure according to certain illustrated embodiments of the present invention, the tube bundle with the tube sheet gasket is inserted into the heat exchanger tube, followed by the spigot element, the element subjected to elastic torsion, and behind them the closure plug element, preferably having a cap and locking ring assembly. In addition, a diaphragm and a diaphragm gasket are provided next to the sealing plug in the heat exchanger tube to ensure tightness. The closure plug is releasably attached to the open-ended channel of the heat exchanger tube by rotating the closure plug coaxially around the longitudinal axis of the heat exchanger in one linear movement, and preferably turning it less than one single revolution to place it in the locked position. It is to be appreciated that the load-bearing surfaces are not in load-bearing contact with each other until the last turn is applied to the closure.

In accordance with certain illustrated embodiments of the present invention, the aforementioned load-bearing surfaces of the closure and the open-ended heat exchanger tube channel preferably include a first set of hubs provided (e.g., by machining) on the closure, and a second complementary set of hubs, provided (for example, by machining) in a portion of the open-end channel of the heat exchanger tube, so that when the closure plug is rotated, the first set of hubs is engaged (interlocked) with the second set of hubs. It should be understood that one or more sets of hub sections may be provided on the closure plug and/or the open-ended heat exchanger channel so that they include an elevated section (e.g., a rail) configured to (i) prevent over-rotation, ( ii) a bearing surface for inserting the closure while (iii) preventing damage to the load-bearing surfaces of both the closure and the open-ended heat exchanger tube channel.

In yet another aspect, a heat exchanger heat exchanger assembly is provided, including an elongated tubular heat exchanger body defining an internal chamber. Within the inner chamber of the heat exchanger housing there is a tube sheet dividing the inner chamber into annular space and intra-channel space. The configuration of the inner section provides for the reception with the possibility of extracting the bundle of pipes located within the annulus of the inner chamber. An annular sleeve element is located within the intra-channel space of the inner chamber of the heat exchanger housing. Within the intra-channel space of the internal chamber of the heat exchanger, an annular element is located, which is subjected to elastic torsion, so that the bushing element is located between the tube sheet and the element, which is subjected to elastic torsion. The element subjected to elastic torsion has an inner circumferential surface deflected relative to its outer circumferential surface for torsion of the element subjected to elastic torsion. In addition, the heat exchanger may further comprise one or more of the following features:

i) a septum baffle assembly, where the sleeve member is located within the intrachannel space of the internal chamber of the heat exchanger housing, for directing fluid from the window passing through the housing to at least two or more pipes in the tube bundle;

ii) a tube sheet spacer positioned between the tube sheet and a shoulder formed within the inner chamber of the heat exchanger body, and a carrier ring positioned within the inner chamber of the heat exchanger shell, with a torsionally elastic element located between the sleeve member and the carrier ring;

iii) at least two windows extending through the housing to allow the entry and exit of fluid into and out of the intra-channel space of the internal chamber of the heat exchanger housing;

iv) while configuring the torsionally elastic element to deflect elastically up to the elastic limit and plastically deflect beyond the elastic limit so that the torsionally elastic element deflects elastically to withstand differential thermal expansion and avoid causing damage to the heat exchanger components when the heat exchanger is under preload and expected pressure load and thermal load;

v) wherein the configuration of the torsion element provides support in a first contact region where the torsion element contacts the sleeve element and in a second contact region where the torsion element contacts the carrier ring;

vi) wherein the element subjected to elastic torsion has a quadrangular cross-section having rounded corners;

- 5 039804 vii) at the same time, a plurality of elements subjected to elastic torsion are sequentially stacked with a foot relative to each other;

viii) wherein the element subjected to elastic torsion is configured to have an outer radius A and an inner radius B, where the outer radius is less than the inner radius of the channel of the inner chamber, which is configured to receive the tube bundle, where the ratio A to B is less than 3;

ix) while configuring the elastically torsion element to have a height H that is approximately 50% of its elastic limit and some thickness T so that the elastically torsion element deforms plastically beyond its elastic limit;

x) a closure assembly for sealing the intra-channel space of the internal chamber of the heat exchanger housing, where the closure assembly includes a locking annular element and a cap element, which are attached with the possibility of detachment to the heat exchanger housing using a locking assembly;

xi) a locking assembly including a plurality of spaced locking ring hub sections configured to properly mate with respective channel hub sections formed at a portion of the cylindrical inner surface of the heat exchanger housing;

xii) a diaphragm positioned so that the intra-channel space of the inner chamber is adjacent to the locking annular and cap members, and a diaphragm gasket pressed against the diaphragm when the locking ring is releasably attached to the heat exchanger body;

xiii) wherein the closure assembly further includes a plurality of first elongated compression elements provided along a portion of the outer radius of the closure assembly so as to transmit force to the first compression ring that transmits force to the diaphragm rim portion and the diaphragm gasket, and a plurality of second elongate compression members provided along the inner radius portion of the closure assembly so as to transmit force to the second compression ring which transmits force to the diaphragm portion causing the diaphragm portion to deflect distally from the closure member towards the member subjected to elastic torsion when the closure assembly attached with the possibility of detachment to the body of the heat exchanger;

xiv) while the configuration of the tube sheet, the sleeve element, the carrier ring, the first and second compression rings, the locking ring and the first and second compression elements ensures that the elasticity remains up to or exceeds the total axial load resulting from the preload, thermal load and pressure load when the closure is attached to the heat exchanger body;

xv) wherein the elongate compressive members are preloaded, the compressive members impart a preload along a first axial load path to a first contact area of the elastic torsion element which transmits the preload along the torsional load path through the elastic torsion element, to a second region of contact of the element subjected to elastic torsion, which transfers the preload along the second path of axial load to the laying of the tube sheet;

xvi) where the stresses imposed by the pressure of the process fluids in the heat exchanger are applied within the usual prescribed threshold range, and the configuration of the element subjected to elastic torsion provides elastic deformation, allowing its outer circumferential surface to move axially towards the closure assembly, while the loads, caused by the pressure of the process fluids in the heat exchanger shell, reduce the stress on the torsion element by deforming the closure distal to the tubesheet, and the torsion element configuration provides elastic deflection up to the elastic limit and plastic deflection beyond the elastic limit. deviations so that the element subjected to elastic torsion can withstand differential thermal expansion in order to avoid causing damage to the components of the heat exchanger when the heat exchanger is under preload conditions. load and expected pressure load and thermal load.

In yet another aspect, a process for assembling a tube heat exchanger assembly is provided, comprising providing an elongated heat exchanger body having an internal chamber defining a longitudinal axis and having an open end of a cylindrical channel. A closure assembly is provided having a closure assembly configured to be secured to the open end of the cylindrical channel of the elongated heat exchanger body. The locking assembly of the closure assembly is inserted into the open end of the cylindrical channel axially along the longitudinal axis of the inner chamber of the heat exchanger so that the load-bearing surfaces of each of the closure assembly and the inner wall of the elongated heat exchanger body do not come into contact with each other. The closure assembly is rotated around the longitudinal axis of the elongated heat exchanger housing to cause the closure assembly to be detachably attached to the cooperating closure assembly provided on the inner wall of the elongated heat exchanger housing to cause the load-bearing surfaces to come into contact with each other in order to transfer the load between the closure assembly. unit and extended heat exchanger. In addition, the tube heat exchanger assembly process may further include one or more of the following features:

i) rotating the closure assembly through less than 360° to cause the closure assembly of the closure assembly to be releasably secured to a cooperating closure assembly provided on the inner wall of the elongated heat exchanger housing;

ii) providing the bayonet closure assembly together with the closure assembly of the closure assembly and the closure assembly provided on the inner wall of the elongated heat exchanger body;

iii) wherein the bayonet closure assembly includes a plurality of spaced closure ring hub sections provided on a portion of the outer surface of the closure assembly, and a plurality of spaced closure ring hub sections provided on the inner wall of the elongated heat exchanger housing, the configuration of which ensures proper closure with the respective hub sections a channel formed on the closure assembly;

iv) before inserting the shut-off assembly, inserting a tube sheet gasket into the open end of the cylindrical channel axially along the longitudinal axis of the elongated heat exchanger body to be adjacent to the channel flange configuration formed in the elongated heat exchanger body, inserting the tube sheet into the open end of the cylindrical channel axially along the longitudinal axis of the elongated body of the heat exchanger for the purpose of being located next to the laying of the tube sheet to limit the annular space and the intra-channel space within the inner chamber of the elongated heat exchanger case, where the configuration of the inner chamber provides for the reception with the possibility of extracting the tube bundle located within the annular space of the inner chamber, insert the annular sleeve element into open end of the cylindrical channel axially along the longitudinal axis of the elongated body of the heat exchanger in order to be located next to the tube sheet, an element is inserted that exposes According to elastic torsion, in the open end of the cylindrical channel along the longitudinal axis of the elongated heat exchanger housing in order to be located next to the bushing element, the carrier ring is inserted into the open end of the cylindrical channel along the longitudinal axis of the elongated heat exchanger housing in order to be located next to the element subjected to elastic torsion, and inserted a diaphragm into the open end of the cylindrical channel along the longitudinal axis of the elongated body of the heat exchanger to be located next to the carrier ring;

v) adjusting a plurality of first outer elongate compression members provided along the outer radius portion of the closure that extend coaxially in the closure along the longitudinal axis of the closure to transfer force to the first compression ring which transfers force to the diaphragm rim portion and the gasket of the diaphragm to compress the diaphragm gasket at the diaphragm, and adjusting a plurality of second internal compression members provided along the inner radius portion of the closure, which extend coaxially in the closure along the longitudinal axis of the closure to transmit force to the second compression ring, which transmits a force on a portion of the diaphragm causing the portion of the diaphragm to deflect distally from the closure assembly to the elastic torsion member of the heat exchange assembly when the closure assembly is attached to the heat exchanger body;

vi) wherein the configuration of the tube sheet, the sleeve member, the first and second compression rings, the closure assembly, and each of the first and second elongate compression members is designed to maintain resiliency up to or exceeding the total axial load resulting from the preload, thermal load and pressure load when the closure is attached to the heat exchanger body;

vii) whereby, when the elongate compression members are preloaded, the compression members impart a preload along a first axial load path to a first contact region of the elastic torsion member which transfers the preload along the torsional load path through the elastic torsion member , to a second area of contact of the element subjected to elastic torsion, which transfers the preload along the second axial load path to the laying of the tube sheet;

viii) while providing resistance to torsional loading by increasing mechanical stress and torsional rotation, allowing you to move the first contact area of the element subjected to torsion, to the tube sheet;

ix) at the same time, the creation of a closure assembly involves positioning a cap element having a cylindrical shape and having an outer diameter that allows fastening concentric with the inner section of the locking annular element having a cylindrical shape, limiting the section of the cylindrical outer surface and the inner section having a cylindrical shape, and the section of the outer surface is equipped with a locking unit of the closure unit.

- 7 039804

In yet another aspect, a closure assembly is provided that is configured to releasably attach to an open end of a channel of an internal chamber of a heat exchanger assembly, comprising a cylindrically shaped locking annular element defining a cylindrical outer surface portion and an inner cylindrically shaped portion. The outer surface section is provided with a plurality of spaced locking ring hub sections, the configuration of which ensures proper closure with the corresponding channel hub sections formed on the section of the cylindrical inner surface of the heat exchange unit. Attached cap element, having a cylindrical shape, is concentric with the inner section of the locking annular element. In addition, the closure assembly may further comprise one or more of the following features:

i) the lid member is releasably attached to the closure ring member, and the closure ring member has an inner diametral surface with a bead configuration that receives the cooperating bead configuration provided on the outer diametral surface of the lid member;

ii) each lock ring hub section extends at a prescribed angle extending from a portion of the outer surface of the lock ring which is configured to properly mate with the respective angled hub sections provided by each channel hub section formed on a portion of the cylindrical inner surface of the heat exchanger assembly;

iii) an upwardly extending flange member provided on the closure ring member configured to stop rotation of the closure assembly into the inner chamber of the heat exchange assembly;

iv) a diaphragm configured to be adjacent to the closure ring and cap;

v) a plurality of adjustable outer elongate closure annular compression members releasably secured in the closure annular element, each elongated closure annular compression member extending through a respective hole formed coaxially with the longitudinal axis in the closure annular member to transmit force to the first a compression ring that transmits force to the diaphragm rim portion and the diaphragm gasket compressed at the diaphragm to position the diaphragm between the diaphragm gasket and the first compression annular member by adjusting the outer elongate locking annular compression members when the locking ring member attached with the possibility of detachment to the inner chamber of the tube heat exchanger assembly;

vi) a plurality of internal adjustable elongated compression lid elements releasably secured in the lid element, each internal elongated compression lid element passing through a respective hole formed coaxially with the longitudinal axis in the lid element to transmit force to the second compression element a ring that transmits force to the diaphragm portion causing the diaphragm portion to deflect distally from the cap member toward the inner chamber of the heat exchange assembly when the closure assembly is releasably attached to the open end of the inner chamber of the heat exchange assembly;

vii) wherein the configuration of the first and second compression rings, compression rods, and compression bolts maintains resiliency up to or exceeding the combined axial load resulting from preload, thermal load, and pressure load when the closure attached with the possibility of detachment to the open end of the inner chamber of the heat exchange unit;

viii) wherein the portion of the outer surface of the closure element is provided with an upwardly extending ridge formed substantially perpendicular to the longitudinal axis of the closure annular element, which is configured to slide into a corresponding groove formed in the portion of the inner surface of the heat exchange assembly perpendicular to the longitudinal axis of the heat exchanger to facilitate insertion locking annular element in the area of the inner surface of the heat exchange unit.

In yet another aspect, a method is provided for operating a heat exchange assembly having a tubular heat exchanger body configured to withstand differential thermal expansion of internal components in an internal chamber of the heat exchanger body during heating and cooling sequences, comprising receiving a preload by an element undergoing elastic torsion, within the inner chamber of the heat exchanger housing, so that the element subjected to elastic torsion takes up the torsional load and elastically deforms to withstand the preload. Perceive the heat load through the heat exchange unit so that the thermal expansion of the internal components in the inner chamber of the heat exchanger body occurs in such a way that the torsional load received by the element subjected to elastic torsion increases, and then it is elastically deformed,

- 8 039804 withstanding the thermal load. In addition, the method of operating the heat exchanger may further include one or more of the following:

i) sensing a pressure load within the internal chamber of the heat exchanger housing, resulting in a reduction in the torsional load taken by the elastically torsion element by elastically deflecting a closure releasably connected to the heat exchanger housing, and relaxing the elastically torsion element so that it can withstand the load caused by pressure;

ii) while the differential thermal expansion of the internal components is that it is possible to withstand the differential thermal expansion of at least the bearing ring, the element subjected to elastic torsion, the bushing element and the tube sheet, without causing plastic deformation of at least the bearing a ring, an element subjected to elastic torsion, and a sleeve element;

iii) wherein the elongated compression members are used to apply a preload to the elastic torsion member so that the compression members impart the preload along the first axial load path to the first contact area of the elastic torsion member which transfers the preload along the path torsional loading through the elastic torsion element into a second contact area of the elastic torsion element which transfers the preload along the second axial load path to the tube sheet;

iv) wherein the torsion element configuration provides support in a first contact region where the torsion element contacts the sleeve element and in a second contact region where the torsion element contacts the carrier ring;

v) inserting a tubesheet spacer into the open end of the cylindrical duct axially along the longitudinal axis of the elongated heat exchanger housing to position adjacent to the channel shoulder configuration formed in the elongated heat exchanger housing, inserting the tubesheet into the open end of the cylindrical duct axially along the longitudinal axis of the elongated heat exchanger housing to location next to the tube grate to limit the annular space and intra-channel space within the inner chamber of the elongated heat exchanger body, where the configuration of the inner chamber provides for the reception with the possibility of extracting the tube bundle located within the annulus of the inner chamber, insert the annular sleeve element into the open end of the cylindrical channel axially along the longitudinal axis of the elongated body of the heat exchanger in order to be located next to the tube sheet, an element subjected to elastic torsion is inserted into the open the end of the cylindrical channel along the longitudinal axis of the elongated heat exchanger body to be located next to the sleeve element, insert the carrier ring into the open end of the cylindrical channel along the longitudinal axis of the elongated heat exchanger body to be located next to the element subjected to elastic torsion, and insert the diaphragm into the open end of the cylindrical channel along the longitudinal axis of the elongated body of the heat exchanger in order to be located next to the carrier ring; and vi) attaching the closure assembly to the open end portion of the inner chamber, the closure assembly including a deflectable diaphragm and a carrier ring and further including a mechanism for imparting a preload to the element undergoing elastic torsion.

It will be easier to understand these and other unique features of the closure disclosed here from the following description and the accompanying drawings.

Brief description of the drawings

Thus, those of ordinary skill in the art to which the proposed systems and methods belong will be able to easily understand how to make and use them, with the help of illustrated various non-limiting possible aspects of the invention in accordance with certain illustrated embodiments, by referring to the drawings, in which in fig. 1A is a partial sectional view of the conventional tubular heat exchanger and closure assembly described in US Pat. No. 4,750,554;

in fig. 1B is a partial sectional view of a tubular heat exchanger and a closure assembly constructed in accordance with the illustrated embodiment;

in fig. 2 is a partial sectional view with callouts of FIG. 1B showing an elastic torsion member according to the illustrated embodiment;

in fig. 3 is a partial sectional view with callouts of a compressed diaphragm seal according to the illustrated embodiment;

in fig. 4 is a partial perspective view of the closure ring element of FIG. 1B in accordance with the illustrated embodiment;

in fig. 5 is a partial perspective view of the inside diameter of the open end portion.

- 9 039804 of the heat exchanger channel according to FIG. 1B;

in fig. 6 is a partial perspective view of the closure element of FIG. 4 inserted linearly into the open end portion of the heat exchanger channel according to FIG. 5 in accordance with the illustrated embodiment;

in fig. 7 is a partial sectional view of a tubular heat exchanger and a closure assembly having multiple elastic torsion members, in accordance with yet another illustrated embodiment; and in FIG. 8 is a partial sectional view of a style B heat exchanger closure assembly in accordance with yet another illustrated embodiment.

Detailed description of some embodiments

Now a more complete description of the present invention is given with reference to the accompanying drawings, which show certain illustrated embodiments of the present invention. The present invention is by no means limited to the illustrated embodiments, as the illustrated embodiments described below are only possible for an invention that could be embodied in various forms, as one skilled in the art would appreciate. Therefore, it should be understood that any details of construction and operation disclosed herein should not be interpreted as limiting, but simply as a basis for the claims and as representative for teaching one skilled in the art the various uses of the invention. In addition, the terms and phrases used herein should not be interpreted as limiting, but rather as providing a clear description of the invention.

Unless otherwise indicated, all scientific and technical terms used herein have the same meaning in which they are usually understood by a person of ordinary skill in the field of technology to which this invention pertains. While any methods and materials similar or equivalent to those described herein are also applicable in the practice or testing of this invention, possible methods and materials will now be described. All patent publications cited herein are incorporated herein by reference to disclose and describe methods and/or materials in connection with the cited publications.

It should be noted that when they are used here and in the appended claims, the singular forms extend to plural indications, unless the context clearly dictates otherwise. Thus, for example, an indication of some stimulus extends to a plurality of such stimuli, an indication of a specific signal extends to one or more signals and their equivalents known to those skilled in the art, and so on.

Well-known components, materials or methods are not necessarily described in detail in order to avoid obscuring the present invention. Any specific details of construction and operation disclosed herein should not be interpreted as limiting, but simply as a representative basis for teaching a person skilled in the art the various applications of the invention. In addition, the terms and phrases used herein should not be interpreted as limiting, but rather as enabling the invention to be used in various ways.

The present invention will now be described more fully, but not necessarily all embodiments will be demonstrated. In addition, we note that many modifications can be made to adapt some particular situation or some particular material to the principles of the invention within the scope of its essential claims.

It is to be appreciated that the present invention eliminates many of the problems associated with prior art heat exchanger closures. For example, referring to FIG. 1A, it is noted that a known closure for a shell-and-tube heat exchanger is shown here, as described in US Pat. The channel has openings to allow access for fluid to enter and exit the bundle tubes. The end closure, or stopper, consists of a locking ring 9 and a cap 19 which includes a diaphragm 8 and a diaphragm gasket 10. The cap assembly is removable, allowing the insertion and removal of a removable tube bundle while maintaining the ability to maintain a tight seal and absorb the resulting high pressure loads. The open channel of the heat exchanger is closed at its end with a stopper assembly (ie cap 19 and locking ring 9). The locking ring element 9 contains a mechanism for sealing the heat exchanger channel at the diaphragm 8 by compressing the gasket 10 with the help of bolts 11 and the compression ring 20.

The annulus fluid is separated from the intrachannel fluid entering the pipes (not shown) by the tube sheet 1 and the tube sheet gasket 6. Typically, the heat exchanger needs a baffle assembly to accommodate a two-pass through-flow arrangement. The baffle assembly may include a sleeve element 2, a baffle plate 3, a baffle cover 4 and/or a ring 17 for directing fluid from the inlet nozzle of the channel through two or more pipe passages to the outlet port. Those skilled in the art will appreciate that the baffle may be applied to either the inlet or the outlet.

Continuing to refer to the known heat exchanger according to FIG. 1A, it is noted that the closure ring 9 is attached to the duct of the heat exchanger casing by means of threads, the closure ring 9 being provided with male threads and the duct provided with corresponding female threads. It should be understood that suitable threads are load-bearing surfaces so that when the heat exchanger is assembled, the threads absorb the preload of the bolts. In addition, during operation of the heat exchanger, a hydrostatic load is applied to the plug cap assembly 19, which in turn is transferred directly to the aforementioned threads.

Turning now to FIG. 1B, note that there is illustrated a partial sectional view of a tubular heat exchanger and a closure assembly constructed in accordance with the illustrated embodiment of the present invention and designated as a unit at 100. Similar to the known heat exchanger of FIG. 1A, heat exchanger 100 is a shell and tube heat exchanger that includes a shell 70, wherein shell 70 has a shell member 15 integral with or connected to channel member 7, shell 70 being configured to receive a bundle of tubes (not shown). The heat exchanger channel element 7 preferably has at least two openings allowing fluid flow to enter and exit the tubes of the insertion bundle. The end closure or closure preferably consists of an annular locking ring element 9, compression rings 21 and 22 and an annular cap element 19. A diaphragm 8 and a diaphragm gasket 10 are also present. The closure plug is removable, allowing the insertion and removal of the removable tube bundle, while retaining the ability to maintain a seal and absorb the resulting high pressure loads during operation of the heat exchanger 100. and locking ring 9). The locking annular element 9 preferably contains means for sealing the heat exchanger channel 7 at the diaphragm 8 by compressing the gasket 10 by means of the bolts 12, the pushers 14 and the compression ring 21. As shown in FIG. 1B, the lid member 19 is releasably attached to the closure ring member 9 so that the closure ring member 9 has an inner diametral surface, preferably formed with a countersinking configuration, which allows the cooperating countersinking configuration provided on the outer diametral surface of the lid member 9 to be received. In the illustrated embodiments, the smallest inner diameter of the lid member 19 is preferably smaller than the largest outer diameter of the closure ring member 9 to form a countersink configuration therebetween.

Continuing with reference to FIG. 1B, the annulus fluid flow is separated from the intraduct fluid flow entering the pipes (not shown) by the tube sheet 1 and the tube sheet gasket 6. Heat exchanger 100 typically needs a baffle assembly to accommodate a two-pass through-flow assembly. However, those skilled in the art will appreciate that the innovative aspects of the present invention could be used with single pass heat exchangers or heat exchangers with more than 2 passes. The baffle assembly in this embodiment includes a sleeve member 2, a baffle plate 3, and a baffle cover 4 for directing fluid from a channel inlet nozzle through two or more conduit passages to an outlet port. It is clear that the baffle can be applied to either the inlet or the outlet.

The closure ring 9 of the closure assembly is attached to the open end portion of the channel 7 of the shell of the heat exchanger 100, preferably by means of a bayonet closure assembly, preferably formed by hub sections 23A and 23B. Referring to FIG. 4-6 (and continuing to refer to FIG. 1B), it is noted that the locking annular element 9 is preferably formed with hub sections 23A formed on a portion of the circumferential outer surface of the annular element 9, with each hub section 23A separated from the others by semi-cylindrical sections 24A without hubs. . Similarly, the open end portion of the channel 7 of the heat exchanger 100 is preferably formed with hub sections 23B formed at the end portion of the inner circumferential surface of the channel 7 of the heat exchanger, separated from others by semi-cylindrical sections 24B without hubs. The plurality of spaced closure ring hub sections 23A belonging to the locking ring 9 ensure proper closure with the corresponding channel hub sections 23B formed on the portion of the cylindrical inner surface of the channel 7 of the heat exchanger 100.

In accordance with the illustrated embodiments, during the assembly of the closure plug (for example, the ring element 9 and the cap element 19) within the end section of the channel 7 of the heat exchanger 100, the locking annular element 9 is inserted into the open end of the cylindrical channel 7 coaxially along the longitudinal axis of the inner chamber of the heat exchanger 100 so that the load-bearing surfaces of each of the annular member 9 and the inner diameter of the open end of the cylindrical channel 7 of the heat exchanger 100 do not transfer the load between the annular member 9 of the closure assembly and the heat exchanger 100, in contrast to the aforementioned known structures and methods. Only after the closure ring 9 is rotated to engage in locking engagement with the elongated heat exchanger 100 is the load transferred from the heat exchanger 100 to the closure plug. This is achieved by pivoting the annular element 9 of the closure assembly about the longitudinal axis of the inner chamber of the elongate heat exchanger 100 to cause detachable bonding of the hub sections 23A of the annular element 9 to the cooperating hub sections 23B provided at the inner diameter of the open end of the cylindrical channel 7 of the heat exchanger 100, facilitating the transfer of load from the channel 7 of the heat exchanger 100 to the annular element 9 of the closure assembly. It should be appreciated that the annular member 9 is rotated less than 360° to cause detachable engagement (correct closure) of the annular member hub sections 23A with the respective hub sections 23B formed at the inner diameter portion of the open end of the cylindrical heat exchanger channel 7 100. In one embodiment, the annular element 9 is rotated approximately 22.5°, where each hub section 23A and 23B extends approximately 22.5° along the circumferential surface portion of the annular element 9 and the open end of the cylindrical channel 7 of the heat exchanger 100 on which they formed accordingly.

It should also be appreciated that in other embodiments, the closure ring element 9 and the cap element 19 may be incorporated in a specific unitary component. In addition, in still other embodiments, the implementation of the locking annular element 9 can be divided into two or more components. In additional embodiments, the hub sections 23A and 23B may have a different shape or design relative to each other in one area of the locking annular element 9.

According to the illustrated embodiments, the configuration of the aforementioned hubs can provide eight sections, so that there are eight sections (23A and 23B) with hubs and eight areas (24A and 24B) without hubs, respectively provided on the annular member 9 and the inner diameter of the open end of the cylindrical channel 7 of heat exchanger 100. However, those skilled in the art will readily appreciate that the number of hub regions can be varied without departing from the innovative aspects of the present invention. For example, there may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 hub areas matching 1, 2, 3, 4, 5, 6, 7, 8, 9 , 10, 11 or 12 areas without hubs.

During assembly of the cap with open heat exchanger channel 7 - and in contrast to the prior art described above - the load-bearing surfaces of the hubs 23A and 23B are not damaged during insertion of the cap assembly into the heat exchanger channel 7. This arrangement also ensures that the diaphragm 8 is properly aligned with the heat exchange channel 7. In addition, it should be understood that the aforementioned hub sections 23A and 23B can be formed (for example, by machining) with a thread pitch such that the cork assembly advances as it is rotated. axially inward into channel 7 of heat exchanger 100.

Continuing with reference to FIG. 4-6 and in accordance with certain embodiments, it is noted that adjacent to the channel hubs 23B or locking ring hubs 23A, or both, an upwardly extending guide member 25 is formed to prevent the hubs 23A, 23B from contacting any of the metal surfaces. during insertion. It should be understood that it may be advantageous to provide guides 25 on the closure ring 9, since manufacturing can be simplified by allowing the closure ring 9 to rotate independently and the channel 7 of the heat exchanger 100 not to rotate independently during manufacture.

According to further illustrated embodiments, an annular upwardly extending anvil 26 (flange) may be provided on the closure ring 9 which corresponds to the location of the diaphragm 8 referred to herein. hub, which is formed when the locking ring 9 is turned in place, closes and foreign material cannot enter it. Note that this facilitates the correct positioning of the cap element 19 and the diaphragm 8 without the need for judgment based on measurements from the outside. This is in contrast to the known designs of screw plugs, in which the location of the locking annular element was determined by the number of turns and thread pitch, which can be changed. The configuration of stop 26 shown in FIG. 6 is to be understood as an exemplary configuration, since other configurations can be envisaged to ensure that a hub-free slot-like cavity is formed when the closure ring 9 is rotated in place and foreign material cannot enter.

As shown in FIG. 4-6, the hub sections 23A, 23B are preferably aligned perpendicular to the longitudinal axis of the closure ring 9 and the channel 7 of the heat exchanger 100. It should be appreciated that in other embodiments, the hub sections can be formed

- 12 039804 (for example, by machining) at some angle relative to the longitudinal axis of the locking ring element 9 and the channel 7 of the heat exchanger 100, so that the locking ring element 9 advances a smaller distance into the channel 7 when the locking ring element is rotated. In addition, the fact that the size and shape of the hubs for hub sections 23A and 23B need not be identical for the entire contingent of hub sections should be appreciated, provided that the length of the locking ring element assembly 9 and channel 7 allows free insertion of the locking ring element 9 into channel 7, and sections 23A and 23B of the hubs of the closure ring 9 and channel 7 correspond to each other.

Turning now specifically to FIG. 6, it is noted that the closure ring 9 of the closure plug assembly is shown to be inserted into the open end of the heat exchanger channel 7. It should be understood that the closure ring 9 is inserted into the channel 7 so that the hubless regions 24A, 24B of the closure ring 9 and the channel 7 respectively allow the hub regions 23A, 23B to slip. For example, the closure plug assembly (shut ring 9) can be loaded into the heat exchange channel 7 at an angle of about 22.5° from the final locked orientation so that the hubless regions 24A, 24B of the closure ring 9 and channel 7, respectively, allow the hub regions 23A, 23B to slip through. in order to prevent the load-bearing surfaces from coming into contact with the guides. As soon as the closure plug is fully inserted into the heat exchanger channel 7, it is rotated to the locked position. For example, the cap assembly can be rotated 22.5° clockwise to the locked position. This rotation can be done in a variety of ways, for example by using a bar bolted to the closure ring 9 to provide sufficient manual rotation of the closure ring 9, or by using a cable connected to the closure ring 9 and a tap to ensure tangential force directed upwards, or through the use of rack and pinion gears mounted in the heat exchanger channel 7 and a corresponding gear mounted on the locking ring element 9, with a lever used to rotate the gear, which in turn applies a tangential force to rotate locking ring element 9. An additional safety feature can be provided by which a groove 27 is provided in one set of hubs of the locking ring element 9, and a corresponding guide groove 28 is formed at the open end section of the heat exchanger channel 7, ensuring that the locking ring element 7 can only be inserted in one orientation with respect to the channel 7.

Referring to FIG. 4, it is noted that the outer markings on the closure ring 9 and the channel 7 can additionally emphasize the correct orientation of the closure ring 9, and on the open end section of the channel 7 near the hub area 24B, a vertical stop 29 having a width that is greater than the width of the guide 27 can be provided. provided in the hub sections 23A to ensure that the hubs 23A and 23B cannot be unintentionally rotated and prematurely engaged during insertion, and at the same time also facilitate the insertion direction of the locking ring 9 so that the hubs 23A and 23B remain protected.

Turning now to FIG. 1B and 3, it is noted that the diaphragm 8 is preferably brought into contact with the duct cover 19 so that the pressure load from the fluid flow in the heat exchanger duct 7 is transferred through the diaphragm 8 to the duct cover 19. The pressure load applied to the duct cover element 19 is then transferred to the closure ring 9. The duct 7 is preferably sealed by a diaphragm gasket 10 . The diaphragm gasket 10 is preferably compressed by a plurality of compression bolts 12 and pushers 14, collectively referred to as compression members, provided axially along the outer row of the closure ring 9, which preferably pass through threaded holes formed in the closure ring 9. These compression elements the bolts 12 and pushers 14 transmit the force to the unloaded outer compression ring 21 provided in the gap between the locking ring element 9 and the diaphragm 8, to the portion of the rim of the diaphragm 8 and the gasket 10 of the diaphragm. It should be understood that the inner row of compression bolts 11, 13 can be placed along the radius of either the annular lid member 19 or the closure ring member 9 as required by the diameters of the elastically torsion member 60 and carrier ring 50 described below.

It is to be appreciated that the diaphragm 8 is preferably configured to deflect by some predetermined amount under bolt preloads and internal pressure such that if the plug assembly is not inserted far enough axially inward into the channel 7 of heat exchanger 100, then the outer row the push bolts 14 of the locking ring element 9 will need to be advanced further to cause sealing by the gasket 10 of the diaphragm, and the inner row of push bolts 13 of the cap element 19 will need to be advanced further to cause the gasket 6 to seal the tube sheet and thereby cause the diaphragm 8 to deform to a greater extent when pressure is applied to channel 7. Dimensional checks can be made during manufacturing time to ensure that machining tolerances are maintained that are acceptable for proper housing placement. After production

- 13 039804 shims can be inserted between the diaphragm 8 and the stopper assembly. Alternatively, the hubs on the closure assembly can be machined in increments such that the closure assembly moves axially inward into the channel 7 of the heat exchanger 100 as it rotates. Rotating the cap assembly until it comes into contact with the diaphragm 8 advances the outer row of push bolts 14 to compress the gasket 21 and then retracts the outer row of push bolts 14, and the cap can be further rotated to minimize the gap. between the closure assembly and diaphragm 8. Once the dimensional control has been carried out, the closure assembly is inserted with linear movement into the channel 7 of the heat exchanger 100, which can be done with a forklift, crane, or other set of equipment already required for beam handling pipes, and therefore - in contrast to the aforementioned known technical solutions, special tools or equipment are not required.

Turning now to FIG. 1B and 3, note the need to understand that during assembly, when the inner row of compression bolts 13 of the cover element 19 is tightened, the axial load is transmitted through the pushers 11 to the unloaded relaxed (inner) compression ring 22 and through the diaphragm 8 to the loading tubular an assembly consisting of a carrier ring 50, an elastic torsion member 60, and a sleeve member 2 to press the tubesheet gasket 6 against the rear face of the tubesheet 1 and casing 15. This axial load is referred to as preload. It should be understood that this preload prevents leakage due to pressure differential between the annular space and the shell of the heat exchanger 100.

In addition, the fact that the aforementioned tubesheet loading assembly preferably withstands thermal loads that cause differential thermal expansion between the channel 7, the tubesheet 1 and the aforementioned tubesheet loading assembly (for example, the bearing ring 50, the element 60 subjected to elastic torsion, and sleeve element 2). Differential thermal expansion is caused by two mechanisms. The first occurs when channel 7 is colder than tubesheet 1 and the tubesheet-loading assembly (e.g., carrier ring 50, torsion element 60, and sleeve element 2) due to the hot process fluid flow that is in direct contact with the tubesheet. contact with the internal components, but is largely shielded from the channel 7 by the sleeve member 2 and by loss of heat present in the channel 7 to the environment or by rapid changes in fluid temperature that cause the temperature of relatively thin internal components to change faster than in a relatively thick channel. Such conditions will inevitably occur during start-up (heating) and during or in the event of a disruption in the production process or a plant shutdown and the subsequent restoration of operating temperature. The second mechanism occurs when the material used to form the channel 7 has a lower coefficient of thermal resistance than the materials used for the tube sheet 1 and the assembly loading the tube sheet (for example, the carrier ring 50, the elastic torsion element 60, and the sleeve element 2 ). For example, this is the case when using carbon steel for channel 7 and stainless steel for the components inside the heat exchanger.

When the combined thermal expansion of the tube sheet 1 and the tube sheet loading assembly (e.g., carrier ring 50, elastic torsion element 60, and sleeve element 2) is greater than the total thermal expansion of the channel 7, the ability to withstand the differential thermal expansion must be ensured by deformation in the heat exchanger 100. Due to the relatively high rigidity of the channel 7 necessary for the safe localization of pressure, the deformation occurs mainly in the relatively less rigid elements in the loading tube sheet node (for example, the carrier ring 50, the element 60 subjected to elastic torsion, and the sleeve element 2 ). If the mechanical stresses caused by this deformation exceed the yield strength of the elements, the result is permanent, or plastic, deformation. Due to the presence of perforations made in the sleeve element 2 to let the fluid into the inner chamber of the heat exchanger 100, said element does not have uniform rigidity throughout its diameter. Therefore, thermal loads can lead to non-uniform plastic deformation of the sleeve element 2, so that restoration of the load on the gasket 22 is impossible simply due to the re-tightening of the inner row of compression bolts 13. When the thermal loads return to normal values, the residual axial compression load in the loading pipe the lattice assembly (bearing ring 50, elastic torsion member 60, and sleeve member 2) is reduced to be less than the loads applied during tightening of the cap member compression bolts 13. This load can be reduced by making it less than the minimum load required to seal the tube sheet gasket 6 if the plastic deformation is severe enough. This results in unwanted leakage between the shell side and the shell side of the heat exchanger 100.

In accordance with the illustrated embodiments, in order to withstand differential thermal expansion without plastic deformation in the heat exchanger, the described

- 14 039804 is now a flexible element. The compliant element is obtained by implementing the elastic torsion element 60 shown in FIG. 1B and 2. As shown, the annular element 60 subjected to elastic torsion preferably comes into contact in the area of the outer circumferential surface in the first area 61 of contact with the sleeve element 2 on the side facing the tube sheet 1, in the vicinity of its outer radius, and contacts on the area of the inner circumferential surface with the carrier ring 50 in the second area 63 of contact on the side facing the diaphragm 8, in the vicinity of its inner radius. When the internal compression bolts 13 are preloaded, axial forces are transmitted through the elastic torsion element 60 in its aforementioned contact areas 61 and 63. These forces, applied at different radii to the elastic torsion member 60, create a torsional load on the elastic torsion member 60, allowing its inner circumferential surface to be deflected relative to its outer circumferential surface in the axial direction to torsion the torsion member 60 with in order to withstand this torsional load by increasing the mechanical stress and torsional rotation, which allows the outer radius of the element 60 subjected to elastic torsion to move towards the diaphragm 8 of the cork assembly, and its inner radius to move towards the tube sheet 1.

It is to be appreciated that the carrier ring 50 protects the diaphragm 8 from damage due to contact by the elastic torsion member 60 during rotation. During operation of the heat exchanger 100, pressure loads will reduce the load on the elastic torsion element 60 by deforming the cap assembly away from the tubesheet 1, but differential thermal expansion will increase the load. It should be understood that the design and configuration of the element 60, subjected to elastic torsion, provide elastic deformation up to the achievement of the maximum required differential thermal expansion. When the loads during operation of the heat exchanger remain below this maximum threshold, the loads in the elastic torsion element 60 will return to the original preload if the thermal and pressure loads are removed. In accordance with the illustrated embodiments, the elastic torsion member 60 may be configured to have a deflection range of 25 mm to 75 mm; however, the element 60 subjected to elastic torsion should not be considered limited by the aforementioned range of deflection, since this element can be configured depending on the size scale of the heat exchanger 100. However, if excessive differential thermal expansion is encountered, as happens during an unintentional thermal deflection of the process fluid, the elastic torsion member 60 plastically deforms to limit the loads applied to the closure assembly to prevent failure of the closure assembly and/or the seal provided by diaphragm 8. It will be appreciated that when thermal loads are removed and pressure loads, loads on elastic torsion member 60 will drop below the initial preload, and may drop to zero. The elastic torsion element 60 can be made from materials that are not susceptible to corrosion, creep, and high temperature buckling, preferably high nickel alloys, including, but not limited to, Inconel 625 and Inconel 718.

Turning now to FIG. 2, illustrative relevant dimensions will now be described for the design of the element 60 subjected to elastic torsion. It should be understood that dimension a is the outer radius, dimension b is the inner radius, dimension h is the height, and dimension t is the thickness of the element 60 undergoing elastic torsion. The dimension a is smaller than the inner radius defined by the channel 7 of the heat exchanger 100, thus providing clearance for radial thermal expansion and rotation under load. The ratio a/b is greater than 1, and preferably less than 3, so that the axial load can create a torsional load in the element 60 subjected to elastic torsion. The dimension h is approximately 50% of the elastic limit of said element when preload and operating loads (pressure and thermal) are applied. The dimension t is chosen so that the axial load is less than the maximum allowable load on the tubesheet gasket 6 when the elastic torsion element 60 is compressed under the sum of the displacement due to the preload and the calculated differential thermal expansion, and that the elastic torsion element 60 , deformed elastically. The material of element 60 subjected to elastic torsion is chosen such that the element will deform elastically when this maximum allowable load is exceeded. It should be understood that the tube sheet 1, the sleeve member 2, the bearing ring 50, the compression rings 22, the compression rods 11 and the compression bolts 13 are designed to remain resilient until the total axial load resulting from the preload is reached or exceeded. thermal load and pressure load.

One should appreciate the fact that in the illustrated embodiments (for example, in Fig. 2 and 3), the element 60, subjected to elastic torsion, is understood as having a

- 15 039804 rectangular cross-section having areas of rounded corners. In alternative illustrated embodiments, other cross-sectional configurations for elastic torsion element 60 may be used, including a rectangular shape or a shape with predominantly rounded sides. In addition, in the embodiments illustrated herein, the tubesheet loading assembly includes a single element 60 subjected to elastic torsion. It should be understood that in some embodiments, in order to meet the design requirements for the minimum pressure applied to the tube sheet 6 and the maximum displacement imparted to the orifice 8, the elastic torsion element 60 can be made with high rigidity so that the maximum thermal expansion without plastic deformation. In such a case, more than one elastic torsion member 60 may be stacked in succession to increase thermal expansion capability. For example, in FIG. 7 shows a design using three elements 60 subjected to elastic torsion. It should be understood that when an odd number of elastic torsion members 60 are used, internal compression bolts (11, 13 and 22) may be provided in the cap flat member 19 at the normal bolt circle radius. And when an even number of elements 60 subjected to elastic torsion are used, internal compression bolts are preferably placed in the locking annular element 9 at a larger radius of the bolt circle. In addition, in designs with multiple members 60 subjected to elastic torsion, a centering ring is preferably included in the composition to maintain alignment of said members with each other.

Turning now to FIG. 3, note that the behavior of the diaphragm 8 is illustrated here after preloading the compression bolts 13 and 14 and applying pressure from the channel 7 of the heat exchanger 100. As shown, at the diaphragm gasket 10, the compression ring 21 moves away from the closure ring element 9 of the closure assembly. , compressing the diaphragm 8 and the gasket 10 of the diaphragm. When pressure is applied from the channel 7 of the heat exchanger 100, the diaphragm 8 deforms until it comes into contact with the closure ring 9 and the cap plate 19 in the region 31. This creates a region of high bending deformations in the diaphragm 8 at a radius smaller than the radius compression ring 21. In order to prevent the diaphragm 8 from breaking, the compression ring 21 is preferably made wider and has a curved surface to reduce bending deformations.

Similar to the outer compression ring 21, the inner compression ring 22 moves away from the closure member 19 of the closure assembly, compressing the diaphragm 8 and the tube sheet loading assembly. As shown, the diaphragm 8 bends around both sides of the inner compression ring 22 when pressure from the heat exchanger channel 7 is applied, creating two regions of high bending strain in the diaphragm 8. To prevent the diaphragm 8 from rupturing, the inner compression ring 22 can also be made wider and made with a curved surface to reduce bending deformations.

In connection with some of the illustrated embodiments described above, it should be understood that the various non-limiting embodiments described herein may be used individually, in combination, or selectively combined for specific applications. In addition, some of the various features of the aforementioned non-limiting embodiments may be used without the corresponding use of the other described features. Therefore, the foregoing description should be considered solely in the context of illustrating the principles, theoretical positions and possible embodiments of this invention, and not in the sense of limiting it.

For example, there are style A and style B vane lock closures. The above illustrated embodiments are of style A, typically used for effluent applications where annulus and shell fluids are not are independent so that the tubesheet can be designed for the pressure drop only. However, the illustrated embodiments should not be understood as being limited to such a style A blade lock type closure, as the invention also encompasses style B closures in which the tubesheet is welded to the channel and does not need to stress the tubesheet gasket, and therefore does not need to and an inner row of bolts, as shown for example in FIG. 8. It should also be understood that the illustrated embodiments can be used with various known methods to achieve internal sealing.

It should be understood that the above arrangements are merely illustrative of the application of the principles of the illustrated embodiments. Those skilled in the art will be able to develop numerous modifications and alternative arrangements within the scope of the illustrated embodiments, and the appended claims are to be considered to cover such modifications and arrangements.

- 16 039804

CLAIM

Claims (22)

CLAIM 1. Heat exchanger node containing an elongated tubular body of the heat exchanger, limiting the inner chamber; a tube sheet located in the inner chamber of the heat exchanger body and separating the inner chamber into an annular space and an intra-channel space, and the configuration of the inner section provides for receiving with the possibility of extracting a bundle of pipes located within the annulus of the inner chamber; a sleeve element having an annular configuration located within the intra-channel space of the inner chamber of the heat exchanger housing; and an element subjected to elastic torsion, having an annular configuration, located in the intra-channel space of the inner chamber of the heat exchanger, and the bushing element is located between the tube sheet and the element subjected to elastic torsion, while the element subjected to elastic torsion has an inner circumferential surface deflected relative to its outer circumferential surface for torsion of the element subjected to elastic torsion; a baffle assembly comprising a spigot located within the intra-channel space of the inner chamber of the heat exchanger housing, for directing fluid from the window passing through the housing to at least two or more pipes in the tube bundle; a tube sheet spacer disposed between the tube sheet and a bead formed within an inner chamber of the heat exchanger body; and a carrier ring disposed within the inner chamber of the heat exchanger body, wherein the element subjected to elastic torsion is located between the sleeve member and the carrier ring. 2. The heat exchange assembly according to claim 1, further including at least two windows extending through the housing to allow fluid to enter and exit the intra-channel space of the internal chamber of the heat exchanger housing and from this space. 3. The heat exchange assembly according to claim 2, wherein the configuration of the torsionally elastic member is elastically deflected up to the elastic deflection limit and plastically deflected beyond the elastic deflection limit, so that the torsionally subjected member deflects elastically, withstanding differential thermal expansion and avoiding causing damage to the heat exchanger components when the heat exchanger is under preload and expected pressure load and heat load conditions. 4. The heat exchange assembly according to claim 3, wherein the configuration of the elastic torsion element provides support in the first contact region, where the elastic torsion element contacts the sleeve element, and in the second contact region, where the elastic torsion element in contact with the bearing ring. 5. The heat exchange unit according to claim 1, wherein the element subjected to elastic torsion has a quadrangular cross section having rounded corners. 6. The heat exchange assembly according to claim 1, further including a plurality of elements subjected to elastic torsion, successively stacked relative to each other. 7. The heat exchange unit according to claim 5, in which the configuration of the element subjected to elastic torsion provides the presence of an outer radius A and an inner radius B, while the outer radius is less than the inner radius of the channel of the inner chamber, the configuration of which provides reception of the tube bundle, where the ratio A to B is less than 3. 8. The heat exchange assembly of claim 7, wherein the torsion element is configured to have a height H that is approximately 50% of its elastic limit and a certain thickness T to cause the torsion element to plastically deform beyond its limit. its elastic deflection. 9. The heat exchange unit according to claim 5, additionally including a closure unit for sealing the intra-channel space of the internal chamber of the heat exchanger housing, and the closure unit includes a locking annular element and a lid element, which are attached with the possibility of detachment to the heat exchanger housing using a locking unit. 10. The heat exchange assembly of claim 9, wherein the shut-off assembly includes a plurality of spaced lock ring hub sections configured to properly mate with respective channel hub sections formed at a portion of the cylindrical inner surface of the heat exchanger housing. 11. The heat exchanger node according to claim 9, further including a diaphragm located so that the intra-channel space of the inner chamber is adjacent to the locking annular and cover elements; and a diaphragm gasket pressed against the diaphragm when the closure ring member is releasably attached to the heat exchanger body. - 17 039804 12. The heat exchange assembly of claim 11, wherein the closure assembly further includes a plurality of first elongate compression members provided along an outer radius portion of the closure assembly to transmit force to the first compression ring that transmits force to the rim portion of the diaphragm. and diaphragm gasket; and a plurality of second elongated compression elements provided along the inner radius portion of the closure assembly so as to transmit force to the second compression ring, which transmits force to the diaphragm portion, causing the diaphragm portion to deviate distally from the cap element to the element subjected to elastic torsion, when the closure is releasably attached to the heat exchanger body. 13. The heat exchange assembly according to claim 12, in which the configuration of the tube sheet, the sleeve element, the carrier ring, the first and second compression rings, the locking ring, and the first and second compression elements maintain elasticity until the total axial load is reached or exceeded resulting from preload, thermal load, and pressure load when the closure is attached to the heat exchanger housing. 14. The heat exchange assembly of claim 13, wherein when the elongate compression members are preloaded, the compression members impart a preload along a first axial load path to a first contact region of the elastic torsion member that transmits the preload along a torsional load path. through the elastic torsion element to a second contact area of the elastic torsion element which transfers the preload along the second axial load path to the tube sheet. 15. The heat exchanger assembly of claim 14, wherein the pressure loads of the process fluids in the heat exchanger are applied within the usual prescribed threshold range, and the element subjected to elastic torsion is configured to elastically deform to allow its outer circumferential surface to axially move towards capping unit; loads caused by the pressure of the process fluids in the heat exchanger housing, reduce the load on the element subjected to elastic torsion, due to the deformation of the closure assembly distally from the tube sheet; and the configuration of the elastically torsion element provides elastic deflection up to the elastic deflection limit and plastic deflection beyond the elastic deflection limit, so that the elastically torsion element withstands differential thermal expansion in order to avoid causing damage to the components of the heat exchanger when the heat exchanger is under preload conditions and expected pressure load and thermal load. 16. A method of operating a heat exchange assembly according to claim 1, comprising a tubular heat exchanger body configured to withstand differential thermal expansion of internal components in the inner chamber of the heat exchanger body during heating and cooling sequences, which consists in receiving a preload by an element subjected to elastic torsion , in the inner chamber of the heat exchanger housing, so that the element subjected to elastic torsion takes up the torsional load and elastically deforms, withstanding the preload; and perceive the heat load by means of the heat exchange unit for differential thermal expansion of the internal components in the inner chamber of the heat exchanger body so that the torsional load received by the element subjected to elastic torsion is increased, and then it is elastically deformed, withstanding the heat load. 17. The method of operation as claimed in claim 16, further comprising sensing a pressure load within the inner chamber of the heat exchanger housing, resulting in a reduction in the torsional load received by the element subjected to elastic torsion, due to the elastic deflection of the closure assembly releasably connected to to the heat exchanger body and relaxing the elastic torsion member to withstand the pressure load. 18. The method of operation according to claim 16, in which the differential thermal expansion of the internal components consists in making it possible to withstand the differential thermal expansion of at least the carrier ring, the element subjected to elastic torsion, the sleeve element and the tube sheet without causing plastic deformation of at least the carrier ring, the element subjected to elastic torsion, and the sleeve element. 19. The method of operation according to claim 16, which uses elongated compression elements to apply a preload to the elastic torsion element, so that the compression elements impart a preload along the first axial load path to the first contact area of the elastic torsion element , which conveys - 18 039804 preload along the torsional load path through the element subjected to elastic torsion into the second contact area of the element subjected to elastic torsion, which transfers the preload along the second axial load path to the tube sheet. 20. The method of operation according to claim 19, wherein the configuration of the elastic torsion element provides support in the first contact region, where the elastic torsion element contacts the sleeve element, and in the second contact region, where the elastic torsion element in contact with the bearing ring. 21. The method of operation according to claim 16, further comprising: inserting a tubesheet spacer into the open end of the cylindrical channel axially along the longitudinal axis of the elongated heat exchanger body to be adjacent to the configuration of the channel bead formed in the elongated heat exchanger body; the tube sheet is inserted into the open end of the cylindrical channel axially along the longitudinal axis of the elongated heat exchanger body in order to be located next to the tube sheet gasket to limit the annular space and the intra-channel space within the inner chamber of the elongated heat exchanger body, the configuration of the inner chamber provides for receiving with the possibility of extracting the tube bundle, located within the annular space of the inner chamber; inserting an annular sleeve element into the open end of the cylindrical channel axially along the longitudinal axis of the elongated heat exchanger body to be located next to the tube sheet; inserting the element subjected to elastic torsion into the open end of the cylindrical channel along the longitudinal axis of the elongated body of the heat exchanger to be located next to the sleeve element; inserting the carrier ring into the open end of the cylindrical channel along the longitudinal axis of the elongated heat exchanger housing to be located adjacent to the element subjected to elastic torsion; and inserting the diaphragm into the open end of the cylindrical channel along the longitudinal axis of the elongated heat exchanger body to be positioned adjacent to the carrier ring. 22. A method for operating a tubular heat exchanger body according to claim 16, further comprising securing the closure assembly to an open end portion of the inner chamber, wherein the closure assembly includes a deflectable diaphragm and a carrier ring and further includes a mechanism for imparting a preload to the element subjected to elastic torsion.